Quantifying the effects of pollen nutrition on honey bee queen egg laying with a new laboratory system

Abstract

Honey bee populations have been declining precipitously over the past decade, and multiple causative factors have been identified. Recent research indicates that these frequently co-occurring stressors interact, often in unpredictable ways, therefore it has become important to develop robust methods to assess their effects both in isolation and in combination. Most such efforts focus on honey bee workers, but the state of a colony also depends on the health and productivity of its queen. However, it is much more difficult to quantify the performance of queens relative to workers in the field, and there are no laboratory assays for queen performance. Here, we present a new system to monitor honey bee queen egg laying under laboratory conditions and report the results of experiments showing the effects of pollen nutrition on egg laying. These findings suggest that queen egg laying and worker physiology can be manipulated in this system through pollen nutrition, which is consistent with findings from field colonies. The results generated using this controlled, laboratory-based system suggest that worker physiology controls queen egg laying behavior. Additionally, the quantitative data generated in these experiments highlight the utility of the system for further use as a risk assessment tool.

Honey Bee Queens and Virus Infections

“…Low sample sizes in the preference tests of individual queen pairs also limited their statistical power but behavioral studies are very time consuming without automation of the assays. Likewise, the test of immune priming was plagued by low sample size; studies of mortality dynamics require much higher sample sizes and replicates distributed across many replicates because of the intrinsic stochasticity of mortality, particularly in laboratory cage studies [101,102]. Finally, the sampling schedule for collecting offspring may also have prevented us from finding an effect because immune priming can be transient [103] and offspring should have been tested at multiple time points after queen inoculation with IAPV.…”

Development of a film-assisted honeybee egg collection system (FECS)

“…The full egg collection capacity of FECS estimated during the spring season (120-180 eggs/2 h), which was almost identical to the intrinsic egg laying capacity of a queen bee, is much larger than the currently reported egg collection efficiency (i.e., 62 eggs/2 h) that was estimated during the fall season. Therefore, the collection efficiency of FECS is likely more dependent upon the egg laying capacity of a queen bee, which changes due to various factors, including seasonal temperature fluctuation, worker bee number, and available food resource (Dunham 1930;Fine et al 2018).…”

“…As the transparent nature of the film enables real-time observation of egg laying from the backside of the comb box, researchers can easily record or mark eggs, thereby allowing collection of a large quantity of eggs with known ages. The queen-monitoring cage (QMC) recently reported by Fine et al (2018) showed that 3D printed artificial comb can be used to monitor egg laying activity of the queen bee and they used the device to evaluate the effect of pollen nutrition on egg laying (Fine et al 2018). Although both FECS and QMC share several common features, QMC is more specialized for monitoring of egg laying under controlled laboratory system whereas FECS is more specialized for mass egg collection from field colonies.…”

Evaluating the impact of jatropha oil extract against the Varroa mite, Varroa destructor Anderson & Trueman (Arachnida: Acari: Varroidae), infesting honeybee colonies (Apis mellifera L.)

“…The state of honeybee colonies depends on the queen's reproductive and health. Thus, the activity of queen, health, and physiological conditions of worker bees can affect the colony through protein nutrition "pollen" (Fine et al 2018). Jatropha seeds content about 33% protein, rich in various macro-elements and micro-elements as Mn, Fe, K, Mg, P, and Na (Abou-Arab and Abu-Salem, 2010).…”